1. Field of the Invention
This present invention relates to a sheet feeding device applicable to an office device such as a printer, a copier and a scanner, and more particularly to a sheet feeding device capable of ensuring the reliability of sheet feeding.
2. The Related Art
With reference to FIG. 1, a common sheet feeding device includes a pick roller 120 and a resilient element 160. The resilient element 160 includes two resilient arms 161 extending and bending rearward from two ends of the resilient element 160. Before paper feeding, the tips of the resilient arms 161 contact the curved surface of the pick roller 120. In operation, the leading ends of the paper sheets push free ends of the resilient arms 161 and then enter between the resilient arms 161 and the pick roller 120. The resilient arms 161 exert a pressure on the paper between the resilient arms 161 and the pick roller 120, which ensures the frictional engagement of the paper with the pick roller 120. With the rotation of the pick roller 120, the paper is drawn forward.
However, once the resilient element 160 is made, the resilient force provided by the resilient arms 161 is limited to be a fixed range. When the resilient force of the resilient arms 161 is unduly large, a few pieces of paper can hardly push away the resilient arms 161 to enter between the pick roller 120 and the resilient arms 161. In a contrary case, when the resilient force of the resilient arms 161 is too small, too many pieces of paper will be able to enter between the pick roller 120 and the resilient arms 161, which will cause malfunction of an office device coupled with the paper feeding component. In other words, the frictional force applied between the paper and the pick roller 120 is not large enough to convey the paper forwardly. So the resilient force provided by the resilient arms 161 is difficult to being confirmed, the accuracy of the sheet feeding is uncertain.